ci: add code coverage

.github/workflows/run-tests.yml

@@ -36,7 +36,7 @@ jobs:
         with:
           php-version: ${{ matrix.php }}
           extensions: dom, curl, libxml, mbstring, zip, pcntl, pdo, sqlite, pdo_sqlite, bcmath, soap, intl, gd, exif, iconv, imagick, fileinfo
-          coverage: none
+          coverage: pcov
 
       - name: Setup problem matchers
         run: |
@@ -53,3 +53,32 @@ jobs:
 
       - name: Execute tests
         run: vendor/bin/pest --ci
+        if: matrix.php != 8.2 || matrix.stability != 'prefer-stable'
+
+      - name: Execute tests with coverage
+        run: vendor/bin/pest --ci --coverage-clover coverage.xml
+        if: matrix.php == 8.2 && matrix.stability == 'prefer-stable'
+
+      - name: Save code coverage to artifact
+        uses: actions/upload-artifact@v4
+        if: matrix.php == 8.2 && matrix.stability == 'prefer-stable'
+        with:
+          name: code-coverage
+          path: "coverage.xml"
+          retention-days: 5
+
+  upload-coverage:
+    runs-on: ubuntu-latest
+    needs:
+      - test
+    steps:
+      - uses: actions/checkout@v4
+      - name: Fetch code coverage artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: code-coverage
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v4
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          fail_ci_if_error: true